The flexibility of additive manufacturing processes allows for complex designs to be produced without the constraints of traditional subtractive manufacturing. However, the high roughness of components built from selective laser melting makes the part unsuitable for many applications without additional post-processing steps. Currently employed finishing techniques have significant limitations such as time-consuming, highly skilled work required with abrasive mechanical polishing or the non-selective process of electrochemical polishing. Laser polishing offers a solution which allows for high selectivity and straightforward automation.

A high-power laser source is used to create a localised melt pool on the surface of the material. The surface tension of the molten material reallocates material on the surface, reducing the roughness. An area is polished by scanning the laser spot across the surface. The small laser spot (typically 50-800 {\mu}m diameter) that is used means that a part can selectively polished. As there is no material removal with this process, no waste is produced.

This paper focuses on the impact of the remelting process on the mechanical performance of Ti6Al4V parts. In particular, a series of measurements of fatigue strength and tensile strength were carried out to compare laser polished and as-built parts, demonstrating a significant improvement in fatigue strength with laser polishing. This is possibly due to the decreased porosity near the surface. The hardness of the surface within the remelted region is also increased but there is no significant change in tensile performance.